Hydrogen gas sensors are essential for industrial safety, environmental monitoring, and the energy sector. As hydrogen infrastructure expands and hydrogen fuel cell vehicles become more widespread, precise detection of hydrogen, which has a wide explosive range, has become increasingly critical. To ensure accurate detection of hydrogen in real-world conditions, sensor technologies must offer high sensitivity, stability, and reproducibility, along with cost-effectiveness, fast response time, and compact design. This study introduces a hydrogen gas sensor based on pressure analysis principles. This sensor was developed to quantitatively evaluate hydrogen uptake, diffusion behavior, solubility, and release characteristics in polymers under high-pressure conditions. Experimental results demonstrated the sensor’s excellent performance, with a stability of 0.2%, a resolution of 0.12 wt·ppm, and a measurement range of 0.12 to 1500 wt·ppm, all within 1 second. Furthermore, the sensor's sensitivity, resolution, and detection range could be tuned to suit different operational environments. Uncertainty analysis showed an expanded uncertainty of 8.8%, confirming the system’s capability for real-time hydrogen detection and characterization. This sensor technology is well-suited for applications in hydrogen refueling stations and fuel cell systems, contributing to the advancement of a safe hydrogen society.

Silicon nitride/cobalt tungsten boride (SiN/CoWB) passivation layer improves mass transport rate at copper thin film layers of semiconductor wafers after chemical mechanical polishing process. This study evaluates mass transport at the interface between copper and passivation layers by stress relaxation method, followed by deduction of interface diffusivity via a kinetic model. For comparison, SiN/CoWB, SiN, silicon carbon nitride (SiCN) and silicon carbide (SiC) passivation layers are introduced. A thin layer of SiN/CoWB demonstrates an outstanding performance as diffusion retarding material, especially at high temperature. The order of stress relaxation in terms of passivation layers is SiN/CoWB < SiN < SiCN < SiC, implying the order of mass transport at the interface. Using the kinetic model, the diffusivities and activation energies regarding passivation layers are calculated and reveal a good agreement with experimental results.